[Intel-gfx] [RFC 00/15] HDMI Audio support on Atom w/o HDAUdio

Pierre-Louis Bossart pierre-louis.bossart at linux.intel.com
Mon Mar 7 18:12:32 UTC 2016

>>> Not sure why you skirt around calling the thing by its name. It's
>>> called LPE isn't it?
>> No. LPE aka SST is the path to the audio dsp subsystem.
>> This path to HDMI has nothing to do with the audio dsp. Not a single
>> gate is shared.
> The why are the interrupt bits called LPE_somethingsomething?
> And what generates the audio data then?

I don't think the HAS ever mentioned LPE, it's really unrelated to LPE. 
LPE cannot even get the interrupts or access the registers.
The audio data is generated by the application, written to a ring buffer 
and fetch by the DMA before they are inserted in the audio islands

>> In most Android implementations this driver is probed using a dedicated
>> ACPI _HID different from the LPEA one. For upstream and machines that
>> don't have this specific device in the BIOS we may piggyback on the LPEA
>> device to complete the probe (that's how it's done on Windows apparently).
> Hmm. So it's a third audio controller or something? Just someone named
> the display related bits as LPE just to confuse people on purpose?

it's really an interface to the display controller, not a new hardware 
part. Everything called LPE should be renamed to avoid this confusion.

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